Improve performance of table trees by around 3x

runtime/observatory/observatory.gypi

 # Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 {
   'variables': {
     'gen_source_dir': '<(SHARED_INTERMEDIATE_DIR)',
   },
   'targets': [
     {
@@ skipping 62 matching lines @@
         'lib/src/elements/class_view.dart',
         'lib/src/elements/class_view.html',
         'lib/src/elements/code_ref.dart',
         'lib/src/elements/code_ref.html',
         'lib/src/elements/code_view.dart',
         'lib/src/elements/code_view.html',
         'lib/src/elements/context_ref.dart',
         'lib/src/elements/context_ref.html',
         'lib/src/elements/context_view.dart',
         'lib/src/elements/context_view.html',
+        'lib/src/elements/cpu_profile.dart',
+        'lib/src/elements/cpu_profile.html',
         'lib/src/elements/curly_block.dart',
         'lib/src/elements/curly_block.html',
         'lib/src/elements/debugger.dart',
         'lib/src/elements/debugger.html',
         'lib/src/elements/error_ref.dart',
         'lib/src/elements/error_ref.html',
         'lib/src/elements/error_view.dart',
         'lib/src/elements/error_view.html',
         'lib/src/elements/eval_box.dart',
         'lib/src/elements/eval_box.html',
@@ skipping 14 matching lines @@
         'lib/src/elements/heap_profile.dart',
         'lib/src/elements/heap_profile.html',
         'lib/src/elements/inbound_reference.dart',
         'lib/src/elements/inbound_reference.html',
         'lib/src/elements/instance_ref.dart',
         'lib/src/elements/instance_ref.html',
         'lib/src/elements/instance_view.dart',
         'lib/src/elements/instance_view.html',
         'lib/src/elements/io_view.dart',
         'lib/src/elements/io_view.html',
-        'lib/src/elements/isolate_profile.dart',
-        'lib/src/elements/isolate_profile.html',
         'lib/src/elements/isolate_ref.dart',
         'lib/src/elements/isolate_ref.html',
         'lib/src/elements/isolate_summary.dart',
         'lib/src/elements/isolate_summary.html',
         'lib/src/elements/isolate_view.dart',
         'lib/src/elements/isolate_view.html',
         'lib/src/elements/json_view.dart',
         'lib/src/elements/json_view.html',
         'lib/src/elements/library_ref.dart',
         'lib/src/elements/library_ref.html',
@@ skipping 90 matching lines @@
             '--dart-executable',
             '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)dart_bootstrap<(EXECUTABLE_SUFFIX)',
             '--directory', '<(PRODUCT_DIR)/observatory/',
             '--command', 'deploy',
           ],
         }
       ],
     },
   ],
 }